MORE DATABASES SHOULD BE SINGLE-THREADED

Summary from the TLDR Dev newsletter

From a DX perspective, every transaction within a shard would always be serializable and never needs to be retried, making it much easier to think about. A single-threaded database would be fully horizontally scalable and have extremely high per-thread throughput, as it wouldn't need to sync with other threads. It would be a much more predictable system. While more restrictive, there would be no more hidden race conditions.